Extra lay-bys are to be retrofitted to the most dangerous stretches of smart motorways amid safety fears.

Highways England has pledged to install a number of additional emergency refuge areas to locations where drivers are most likely to stop in live lanes.

The government-owned company will also reduce the maximum gap between lay-bys in future schemes from 1.5 miles to one mile “where practicable”, to provide “greater reassurance to road users”.

The decisions were made following a safety review by Highways England.

Smart motorways boost capacity by using the hard shoulder for traffic, meaning vehicles that suffer a breakdown or accident may have to stop in a live running lane if they cannot make it to a refuge area.

Sections of motorways such as the M25, M1, M4 and M6 have already been converted and another 480 smart motorway lane miles are planned.

Motoring groups have lobbied the Department for Transport for several years over fears that the perceived lack of lay-bys is putting drivers at risk of being hit from behind if they need to stop suddenly.

Drivers described smart motorways as “death zones” and the refuge areas as “desperate unreachable havens” in a 2016 AA questionnaire.

On Friday a family recalled the horror of being hit by a lorry at up to 60mph after breaking down on a section of the M6 which had no hard shoulder in preparation for becoming a smart motorway.

Duncan Montgomery, who was in the car with his wife and their three daughters, told Channel 4 News: “Glass was smashed everywhere, the whole side of the van was halfway across the carriage.

“I got Rose (his daughter) and dragged her into the front driver’s seat where she was throwing up blood.”

The family escaped with minor injuries from the crash, which happened over the festive period in Cheshire.

AA president Edmund King described the increase in the number of lay-bys as “victory for common sense”.

He said: “Improving capacity and easing congestion on our motorways is key for the economy, but not at the expense of safety.